Thin surfaces restrained by a supporting structure naturally bellied out under air pressure, assuming what we now call a “cambered” - that is, arched - shape. Neither the feathers of birds nor the fabric of sails and windmill blades had any thickness to speak of, and so the earliest lifting surfaces were just that: surfaces.
It was also perfectly evident to any thinking person that what kept birds and bats aloft was the large flat surfaces attached to their arms. Two early applications of it, the windmill and the fore-aft rigged sail, date back at least 800 years. That flat surfaces in the wind could produce the sideways force that we now call lift was a very ancient observation. A flat sheet makes a perfectly serviceable wing. Model planes with flat sheets of balsa wood for wings fly nicely so do airplanes made of folded paper, and bumblebees and butterflies. The episode features Josh and James and covers Josh Bixler’s approach to designing Flite Test airplanes with aerodynamics in mind.Let’s be frank. If you want to learn more about aerodynamics and you’re interested in the subject, here’s a recent Flite Test podcast all about it. How am I going to manufacture the wing in the first place?Īerodynamics Podcast Episode with Josh Bixler What will the wing shape (swept, tapered, etc) be? What will be the wing-loading and power range of my aircraft?
WING AIRFOIL TRIAL
Working through a trial and error procedure is one of the best (and most rewarding) ways to learn. Test it out and then tweak something on the next version. The best way to choose an airfoil is to start by thinking about what experience you want to have and how you’re going to manufacture the wing.Ĭhoose the type you think best fits your needs and go for it. You shouldn’t have to agonize over the differences between closely related NACA airfoils - there will be virtually no perceived difference to your flight experience. They work by displacing air in a vortex pocket behind the step.Īs mentioned previously, the secret of choosing the correct airfoil is not to overthink it.
A Kline-Foglean (KF) airfoil is one such type that is commonly used due to its ease of construction. Aircraft like the FT Viggen use angled canards to help provide lift.Īgain, for simple models that don’t fly all that fast. Flown at a high angle of attack, flat-bottomed wings are probably the simplest to make but can perform fairly poorly. One way to add reflex is to simply trim the wing's elevons slightly upward.įor simple models. Check out this article on how flying wings fly to find out more. The trailing edge is upturned slighting which provides stability. You can under camber just the outer section of a wing to increase stability.įor flying wings. Provide lots of lift but are quite draggy. They’re simple to manufacture, draggy (which is sometimes good for creating a stable flight experience) but are often sensitive to changes in airspeed which makes them difficult to trim.įor small, lightweight airplanes. Excellent lift-drag ratio.įor easy to build airplanes. Great for precision aerobatics.įor sport planes, semi-aerobatic planes and sailplanes. Let’s break down the main categories to give you a better idea of which airfoil is right for your airplane. The thickness of this airfoil is always 11.7% of the chord.
WING AIRFOIL CODE
NACA airfoils - These airfoils map a four-digit code to an airfoil to indicate camber, chord and thickness specifications.Reading up about them might be a good way to learn about the nuances of how designers create airfoils. Getting more into the technical and mathematical side of airfoil design, here are two popular names that you may see when researching airfoil shapes.
Here are eight of the most commonly used airfoils used on RC model airplanes (in no particular order): It is possible to boil types of airfoils down to into various categories. It all depends on the application the environment in which the airfoil operates dictates its size and shape. Airfoils come in a whole range of shapes and sizes, both in the aerospace industry and in nature - really, nothing is standard.
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